1. Field of the Invention
This invention relates to gas turbine combustors and more specifically to a measurement device for quantifying combustor static and dynamic pressure levels as well as temperature.
2. Description of Related Art
It is a well known requirement to measure and monitor the pressure and temperature levels within a combustion system in order to ensure acceptable system durability and reliability. Within a combustion system, pressure fluctuations occur as part of the combustion process, and this is especially common with fuel-lean combustion systems. As combustion systems become more air-rich due to a lower fuel/air ratio, stability of the flame within the combustor becomes a concern. It is this instability that is a common driver of combustion dynamics. Excessive combustion dynamics can cause premature failure and require replacement of combustion hardware. Typically, a variety of equipment is required in order to measure the static pressures, dynamic pressures, as well as temperature. Combustion systems of the prior art have been known to use internally mounted dynamic pressure transducers, externally mounted accelerometers, or optical sensors to detect combustion dynamic pressure levels. With externally mounted accelerometers, only dynamic pressure was recorded. Optical sensors correlated spectral acoustic frequency of the ultraviolet flame emission with dynamic pressure waves characteristic of combustion dynamics. Meanwhile, static pressure levels were obtained by mounting separate pressure taps at the areas of interest while temperatures were measured through individual thermocouples.
While each of these devices may be acceptable individually to measure dynamic pressure, static pressure, or temperatures, multiple installations of costly instrumentation are required in order to capture all three types of data. What is needed is a device that can perform all of the above-described functions while requiring minimal installation time and at a reasonable cost.
The invention facilitates the acquisition of combustor diagnostic information such as dynamic pressure fluctuations, static pressure levels, combustion system pressure drop for mass flow correlation, and temperature with minimal equipment, installation time, or capital investment. In an exemplary embodiment a probe, which can easily be removed from a combustor, is connected to an instrumentation assembly that is capable of simultaneously measuring dynamic pressure, temperature, and at least one static pressure for a gas turbine combustor. The ease of installation allows rapid performance point benchmarking of different ambient day conditions. This information is critical to ensure low emissions operations over a range of ambient conditions. The removable probe is utilized in an instrumentation assembly that includes a plurality of conduits fixed to the probe as well as means for measuring and recording each of the pressures and temperatures.
It is an object of the present invention to provide a removable probe for use in a gas turbine combustor wherein the probe is capable of simultaneously measuring dynamic pressure, temperature, and at least one static pressure.
It is a further object of the present invention to provide a removable instrumentation assembly requiring minimal installation time and reduced cost.
In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.